The BioWare Blog has details on Operation: BALLISTIC, the latest weekend event for Mass Effect 3, the sci-fi RPG/shooter sequel:

Operation BALLISTIC (Jan 25th-27th)

Event Description: Recon has new estimates on the number of Reaper creatures, and the news is dire. Each of you must inflict as many casualties as possible, and we must destroy husk-creation mechanisms like Dragonís Teeth. If we fail to accomplish this, we will be even more outnumbered in the coming days.